Centrifuge

ABSTRACT

A centrifuge including flexible tubes in fluid communication with containers for a sample being centrifuged and having portions extending into the containers. The containers are held in a ring which is detachably secured to the centrifuge rotor. The device includes means for withdrawing those portions of the tubes which extend into each container inwardly towards the center of the centrifuge a distance sufficient to permit the ring holding the containers to be freely raised off the centrifuge rotor. In a preferred embodiment, the tubes are in liquid communication with a chamber for holding a liquid and motion of the chamber either axially or rotatably or both with respect to the rotor withdraws the conduits from the liquid containers.

United States Patent Unger et al.

[451 Aug. 15, 1972 [54] CENTRIFUGE [72] Inventors: Hans Peter Olof Unger, Stockholm;

Johan Eric Hayden Westberg, Lidingo, both of Sweden [73] Assignee: AGA Aktiebolag, Lidingo, Sweden 22 Filed: Aug. 17,1970 [21] Appl. No.: 64,354

[30] Foreign Application Priority Data Aug, 22, 1969 Sweden ..1 1689/69 [52] US. Cl .233/26 [51 Int. Cl ..B04b 9/12, B04b 9/14 [58] Field of Search ..233/l R, 26, 22, 21; 23/259; 128/214; 222/134 [56] References Cited UNITED STATES PATENTS 3,401,876 l/l968 Lucas ..233/26 3,175,732 3/1965 Unger ..222/134 Primary Examiner-Jordan Franklin Assistant Examiner-George H. Krizmanich Attorney-Larson, Taylor and Hinds 5 7] ABSTRACT A centrifuge including flexible tubes in fluid communication with containers for a sample being centrifuged and having portions extending into the containers. The containers are held in a ring which is detachably secured to the centrifuge rotor. The device includes means for withdrawing those portions of the tubes which extend into each container inwardly towards the center of the centrifuge a distance sufficient to permit the ring holding the containers to be freely raised off the centrifuge rotor. In a preferred embodiment, the tubes are in liquid communication with a chamber for holding a liquid and motion of the chamber either axially or rotatably or both with respect to the rotor withdrawsthe conduits from the liquid containers.

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ATTOINEYS CENTRIFUGE BACKGROUND OF-THE INVENTION The present invention relates to a centrifuge. In one aspect, the invention relates to a rotor assembly for a centrifuge. In another aspect the invention relates to such assembly having conduits in liquid communication with containers holding liquid being centrifuged. In still another aspect, the invention relates to such centrifuges and centrifuge assemblies for treatment of samples, such as blood, which comprise a liquid with solid particles distributed therein.

It is known to treat blood by centrifuging. It is further known to repeatedly wash the blood cells during the centrifuging process. In one type of conventional centrifuge, the samples are in test tube containers placed in a ring concentric with the centrifuge rotor. A feed tube which is utilized, for example, to introduce wash water into the test tube, extends into the test tube and terminates near the bottom thereof.

For certain blood examinations, it is necessary that the blood cells are incubated at 37C with serum. Subsequently, the blood cells must be washed a number of times for the removal of protein not specifically bonded to the blood cells. Only after removal of this protein can a reagent be added to permit determination of a possibly occuring agglutination of the cells.

In conventional centrifuges of the type described, the insertion and removal of the test tubesnecess'itated in this process has been time-consuming, particularly because of the accuracy and care which has to be observed to ensure that the flexible tubes do not become contaminated by samples in the test tubes and because of the risk of confusion and contamination of the samples. It is an object of the present invention to provide a centrifuge having tubes in liquid communication with the liquid being centrifuged which is free of the disad vantages mentioned above. It is a further object to provide such centrifuge wherein the test tubes or other containers for the liquid being centrifuged are easily removed from the centrifuge with minimum risk of contamination or confusion of the samples.

BRIEF SUMMARY OF THE INVENTION The foregoing and other objects which will be apparent to those having ordinary skill in the art are achieved according to the present invention by providing a centrifuge rotor assembly comprising a rotor, a ring mounted for rotation concentrically on said rotor for holding a plurality of containers for sample liquid to be centrifuged and a plurality of conduits each having a portion extending downwardly into each of said containers for liquid communication therewith, the improvement wherein said ring is detachably secured to said rotor for removal therefrom, wherein each of said conduits comprises a flexible tube, and wherein said centrifuge includes means for withdrawing said portions of said tubes inwardly towards the center of the centrifuge a distance sufficient to permit said ring holding said containers to be freely raised off the centrifuge rotor.

DESCRIPTION OF PREFERRED EMBODIMENTS There follows a detailed description of a preferred embodiment of the invention, together with accompanying drawings. However, it is to be understood that the detailed description and accompanying drawings are provided solely for the purpose of illustrating a preferred embodiment and the the invention is capable of numerous modifications and variations apparent to those skilled in the art without departing from the spirit and scope of the invention.

FIG. 1 is a sectional elevation of one half of a centrifuge rotor assembly according to the invention;

FIG. 2 is a. plan view partially in section, of one half of an alternative centrifuge rotor assembly according to the invention; and

FIG. 3 is a sectional elevation of one half of a further alternative centrifuge rotor assembly according to the present invention.

In view of the fact that in all cases the centrifuge is rotation-symmetrical in respect of the centrifuge shaft only thedetails of the assembly on one side of this shaft are shown.

The centrifuge shown in FIG. 1 includes a motor 1, and is provided with a drive shaft 2, which supports the centrifuge rotor 3. Rotor 3 comprises a central portion 4, which is secured directly to the drive shaft 2, and to which is'connected detachably a ring 5, in which are placed a number of test tubes 6. The centrifuge rotor 3 also comprises a distribution chamber 7, into which is introduced a conduit not shown for feeding liquid to chamber 7. Tubes 6 contain a liquid to be centrifuged such as blood. The liquid introduced into chamber 7 may therefore be wash liquor for washing the blood cells in the blood in the test tube 6. A number of flexible tubes 8 connected on the periphery of the distribution chamber 7 for supplying washing liquor from the distribution chamber 7 to the test tube 6 project down into the test tubes 6 and end near the bottom of them. Tubes 8 thus place chamber 7 and tubes 6 in liquid communication for the supply of wash liquor from chamber 7 to the test tubes. The feed tubes 8 pass through guides 9 in the centrifuge rotor which guide the tubes into the opening in the upper ends of the test tubes. Any excess washing liquor which is introduced during the washing procedure is discharged from the centrifuge by conventional conduits arranged in a manner 'known per se.

In the embodiment shown in FIG. 1, ring 5 is detachably connected to the central portion 4 of the centrifuge rotor by a number of pins 10 distributed around the periphery on the ring which project down into holes 11 in the central portion 4. To make it possible to lift ring 5 with its test tubes off the central portion of the rotor, the feed tubes must be drawn in towards the center of the centrifuge rotor. In the embodiment according to FIG. 1 this is accomplished in that the chamber 7 is axially displaceable in relation to the centrifuge rotor such that the feed tubes 8 are moveable into the position indicated by broken lines in FIG. 1. The chamber 7 is controlled during this lifting operation by a linkage 12 consisting of two lever arms 13 and 14, the first of which is hinged to the chamber 7 at 15 and the other is hinged to the central portion 4 at 16. The arms are connected moreover via a bearing 17 and are acted on by a tension spring 18 under the effect of which the lever arms can assume two stable positions: a first position indicated in full lines with tubes 8 extending into the test tubes; and a second position indicated in broken lines with tubes 8 withdrawn from the test tubes. In the latter position, the portion of each feed tube 8 which was previously in each test tube 6 is drawn upwardly toward the center of the centrifuge a distance sufficient that ring 5 with its test tubes 6 can freely be raised off the centrifuge rotor.

Another possibility for freeing the ring from the test tubes is shown schematically in FIG. 2, wherein the centrifuging assembly is seen from above. The top part of this figure shows the assembly in the position where the flexible feed tubes 8" are inserted in the test tubes 6, while in the bottom half of the figure a position is shown where the flexible feed tubes 8 are drawn in towards the center to such an extent that the ring 5 with the test tubes 6' can be lifted off the centrifuge rotor. In this case the chamber 7 is rotatable around the centrifuge shaft to the position shown in the bottom half of the figure, the feed tubes 8 being guided by guides 9 in the central portion 4 of the centrifuge rotor.

The embodiment shown in FIG. 3 may be regarded to a certain degree as a combination of the embodiments according to FIG. 1 and 2. Here the chamber 7" is both axially displaceable and rotatable in relation to the central portion 4" of the centrifuge rotor. This has been achieved in that the chamber 7" is rotatable in a helical track on the central portion 4", so that a rotation of the chamber 7" in relation to the rotor also results in an axial displacement of the chamber. As a consequence the height of the centrifuge can be reduced.

What is claimed is:

1. In a centrifuge rotor assembly comprising a rotor, a ring member rotatably mounted concentrically on said rotor and including means for holding a plurality of containers for sample liquid to be centrifuged, and a plurality of conduits each having a portion extending downwardly into each of said containers for liquid communication therewith, the improvement wherein: said ring member is detachably secured to said rotor for removal therefrom in a direction axially of said rotor; each of said conduits comprising a flexible tube movable from an extended position with its outlet end within said container and a retracted position with its outlet end withdrawn out of said container towards said rotor whereby said tubes are withdrawn out of said containers inwardly towards the center of the centrifuge a distance sufficient to permit a ring member holding said containers to be freely raised off the centrifuge rotor with said containers held thereby in a direction axially of said rotor; and means for moving said tubes between said retracted and said extended positions.

2. An improved centrifuge rotor assembly according to claim 1 further including a chamber for holding liquid, said flexible tubes in said extended position extending from said chamber to said containers for liquid communication therebetween, and guide means for guiding each of said flexible tubes into an opening of a container.

3. An improved centrifuge rotor assembly according to claim 2 wherein said assembly includes means for ermitting axial displacement of said chamber relative o the centrifuge ro or for withdrawing said tubes from said containers.

4. An improved centrifuge rotor assembly according to claim 2 wherein said assembly includes means for permitting rotation of said chamber relative to the centrifuge rotor for withdrawing said tubes from said containers.

5. An improved centrifuge rotor assembly according to claim 2 wherein said assembly includes means for permitting axial displacement and rotation of said chamber relative to said rotor for withdrawing said tubes from said containers. 

1. In a centrifuge rotor assembly comprising a rotor, a ring member rotatably mounted concentrically on said rotor and including means for holding a plurality of containers for sample liquid to be centrifuged, and a plurality of conduits each having a portion extending downwardly into each of said containers for liquid communication therewith, the improvement wherein: said ring member is detachably secured to said rotor for removal therefrom in a direction axially of said rotor; each of said conduits comprising a flexible tube movable from an extended position with its outlet end within said container and a retracted position with its outlet end withdrawn out of said container towards said rotor whereby said tubes are withdrawn out of said containers inwardly towards the center of the centrifuge a distance sufficient to permit a ring member holding said containers to be freely raised off the centrifuge rotor with said containers held thereby in a direction axially of said rotor; and means for moving said tubes between said retracted and said extended positions.
 2. An improved centrifuge rotor assembly according to claim 1 further including a chamber for holding liquid, said flexible tubes in said extended position extending from said chamber to said containers for liquid communication therebetween, and guide means for guiding each of said flexible tubes into an opening of a container.
 3. An improved centrifuge rotor assembly according to claim 2 wherein said assembly includes means for permitting axial displacement of said chamber relative to the centrifuge rotor for withdrawing said tubes from said containers.
 4. An improved centrifuge rotor assembly according to claim 2 wherein said assembly includes means for permitting rotation of said chamber relative to the centrifuge rotor for withdrawing said tubes from said containers.
 5. An improved centrifuge rotor assembly according to claim 2 wherein said assembly includes means for permitting axial displacement and rotation of said chamber relative to said rotor for withdrawing said tubes from said containers. 